Field
Embodiments of the disclosure relate generally to the field of lock bolts for composite and metal structures and more particularly to temporary clamp systems for tightening of lock bolts to induce sealant squeeze-out prior to collar fixation on the lock bolt for lock bolts employed with fay-seal applications.
Background
Composite and metal structures having joints with fay surface sealant are often assembled with lock bolts, sleeved lock bolts or sleeved threaded lock bolts. For such applications, it is often necessary to apply a temporary clamp load for an extended period of time, twenty minutes in exemplary applications, to allow the sealant to flow away from the fastener before the final nut tightening or swaging can be completed. Current solutions employ a temporary threaded pin fastener received in the fastener hole in the composite with a head on a first surface of the composite structure and engaged with a temporary threaded nut tightened against a second opposite surface of the composite structure. The entire temporary fastening system, pin and nut, are removed after sealant squeeze out has been accomplished and replaced with a permanent lock bolt and associated swaged collar. This may adversely impact assembly time and handicap automated assembly solutions.
It is therefore desirable to provide a sealant squeeze-out system providing tension on a standard lock bolt.